Synthesis of octadienyl esters

ABSTRACT

OCTADIENYL ESTERS ARE PREPARED BY REACTING BUTADIENE WITH CARBOXYLIC ACIDS IN THE PRESENCE OF PALLADIUM CATALYSTS, PREFERABLY COMPLEXED WITH PHOSPHITE OR PHOSPHINE LIGANDS, AND TERTIARY AMINES HAVING A BASICITY CONSTANT KB GREATER THAN 10**-7 AS REACTION MODIFIERS. THE TERTIARY AMINES ALSO ASSIST IN THE SEPARATION OF THE PRODUCTS.

United States Patent 3,711,534 SYNTHESIS OF. OCTADIENYL ESTERS Robert M. Manyik, St. Albans, and Wellington E. Walker, Charleston, W. Va., assignors to Union Carbide Corporation, New York, N.Y. v,

No -Drawing. Filed Sept. 4,-1968, Ser. No. 757,485 Int. Cl. C07c 69/54, 69/80 U.S. Cl. 260-475 N I 23 Claims ABSTRACT OF THE DISCLOSURE Octadienyl esters are prepared by reacting butadiene w th carboxylic' acids in the presence of palladium "catalysts, preferably complexed with phosphite or phosphine ligands, and tertiary amines having a basicity constant K greater than as reaction modifiers. The tertiary amines also assist in the separation of the products.

v This invention relates to an improved process for making octadienyl esters.

It is already .known to produce octadienyl esters by the simultaneous dimerization and reaction of butadiene with carboxylic acids in the presence of palladium or platinum catalysts. A process of this nature is described in I. E. McKeon and D. R. Bryant application Ser. No. 660,226, filed Aug. 14, 1967 now U.S. Pat. No. 3,534,088, and

"more particularly, one which is carried out in the presence of a source of carboxylate ion, such as potassium or sodium acetate. While this is a useful process, the yields at equivalent temperatures, they markedly increase the conversion of butadiene, and they improve the efficiency v of the reaction to octadienyl esters. These eifects of the amines, .in addition to being asource of carboxylate ion,

shown to be beneficialby McKeon and Bryant, may be attributed to their forming complexes with the palladium catalyst leading to amore active catalyst. On the other hand, sodium and potassium acetate are. incapable of forming complexes with palladium catalysts.

A representative numberof tertiary aliphatic amines have been investigated and all significantly enhance the "activity of the palladium catalyst. Thus, effective amines .include trime thylamine, triethylamine, triisopropylamine, ftrib'utylamine and .the like; oxygen-substituted tertiary amines, such as N-methylmorpholine, Z-dimethylamino- "ethanol, 2 dimethylaminoethylacetate, 2 diethylaminoethanol, methyldiethanolamine, triethanolamine and 3-dimethylamino-l-propanol; and tertiary diamines, such as N,N,N,N-tetramethyl-1,3 propanediamine, N,N,N',N'-

f tetramethyl-l,3 butanedi-arnine, N,N,N,N tetramethyl ethylene di-amines-and triethylene diamine. Weakly basic aromatic amines, "such as pyridine, having a basicity cons'ta'nt, K =1.4 l0-?"have been shown to be ineffective in increasing the activity of the'c atalyst, and it is therefore i believed that all tertiary 'amineslhaving a basicity equi- 'fvalent to, the tertiary aliphatic amines mentioned above wouldbeeifective 'irijthe'iprocess of this invention (i.e., ibenzylpyrrolidine).Tlius, tertiary amines having a basicity constant Ki, greater than 101", and preferably in the range V to 10- arel preferredin the practice of the inavention. t .l

' As'meiitionedfiu the'McK'eonand Bryant patent application Ser. No. 660,226, the reaction of butadiene with acetic acid accordingto the present invention is funda- -"mentally' different from-the olefin-acetic acid reactionsdescribed in U.S. Pat. No. 3,221,045 issued to I. E. McKeon and P. S. Starcher, and the only similarity is in the reference to palladium catalysts. Thus, the presence of a catalytic co-oxidant, i.e., Cu(II), is not necessary for the butadiene dimerization reaction of the present invention, and if present, greatly favors the formation of butenyl esters, rather than the octadienyl esters.

The butadiene dimerization and addition reaction of this invention differs from that described in U.S. Pat. No. 3,221,045, not only in that catalytic co-oxidant is not needed in the process of this invention, but also in that the reactions of this invention are carried out under nonoxidizing conditions and no water is produced in the process. For example, the reaction of ethylene, oxygen, and acetic acid to produce vinyl acetate may be written as follows:

On the other hand, the butadiene reaction of this invention may be represented as follows: 2CH =CH-CH=CH +CH COOH As shown in the equations above, all the hydrogen atoms present in the two molecules of butadiene and the molecule of acetic acid appear in the final octadienyl acetate; none is oxidized to water.

As previously mentioned, it is important to carry out the reaction under non-oxidizing conditions. Oxygen is not required to support the butadiene dimerization and addition reaction of this invention, but is also deleterious, if

present in significant amounts. Thus, in the presence of oxygene, the starting 1,3-dienes readily form peroxides, as do the octadienyl ester products. Such peroxides lead to undesired radical induced polymerization reactions, and resulting low yields, if any, of the desired products. Oxygen also has an unfavorable effect on the phosphorus containing ligands, which are often included in the palladium catalyst, leading to the oxidation ofP(IIl) to P(V) yielding phosphine oxides and phosphates which are ineffective in promoting the palladium catalysts.

The octadienyl esters formed in the process of this invention are primarily 2,7-octadien-l-ol acetate, although small amounts of the secondary acetate, 1,7-octadiene-3-ol acetate, are also formed. Upon hydrogenation and bydrolysis, the primary acetate is readily converted to octanol-l, which is desirable for making dioctyl phthalate, an important plasticizer. The secondary acetate can also be converted to the alcohol by hydrogenation and hydrolysis, although secondary alcohols are less desirable for making plasticizers. However, such secondary alcohols can be converted to useful nonionic surfactants by reaction with ethylene oxide.

The use of the tertiary amines as catalyst modifiers has also provided an unexpected benefit in the separation process. At the conclusion of the reaction, the volatile products are stripped from the crude reaction mixtur'e, leaving a catalyst residue for recycle to the. reactor. In distilling the volatile products, it would normally be expected that the primary ester and the secondary ester would distill together since their boiling points are close together. However, it has been found that the secondary ester- -first.-distills over as an azeotrope with the tertiary .amine and with the tertiary amine-acetic acid azeotrope,

leaving the purified primary ester as a residue or as a second distillate,,if there is enough amine present to .can be derived from a palladium compound which is soluble in the reaction mixture or which can-become soluble therein by reaction with one of the components of said mixture. Illustrative palladium compounds which may be used include palladium(II) alkanoates, e.g., palladium(II) acetate, palladium(II) propionate, palladium (II) butyrate, palladium(II) hexanoate, and the like; the palladiumfll) cycloalkanecarboxylates, e.g., palladium- (II) cyclohexanecarboxylate, and the like; palladium(II) aryl carboxylates, e.g., palladium(II) benzoate, palladium- (II) monomethyl phthalate and the like; olefin complexes of palladium, 1,5-cyclooctadiene palladium(II) chloride, 1r-allylpalladium acetate, endo-dicyclopentadienepalladium(II)bromide and the like; complexes with alkyl and aryl nitriles, e.g., bis(benzonitrile)palladium- (H) chloride, bis(propionitrile)palladium(II) cyanide, and the like; palladium(II) bromide, palladium(l'I) nitrate, palladium(II) sulfate, palladium(lI) acetylacetonate, ammonium chloropalladate, ammonium chloropalladite, potassium bromopalladite, dichlorodiamminepalla dium(II), dinitritoamminepalladium(II), potassium chloropalladate, potassium chloropalladite, sodium chloropalladite, and the like; complexes of palladium with trihydrocarbylphosphines and arsines, e.g.,

bis(triphenylphosphine)palladium(II) acetate, tetrakis( triphenylphosphine )palladium tetrakis(dimethylphenylphosphine)palladium(0), bis(triphenylphosphine)palladium(II) nitrate, bis(triphenylarsine)palladium(II) chloride, bis(dimethylphenylphosphine)palladium(II) chloride, bis(tributylarsine)palladium(II) bromide, bis(trioctylphosphine)palladium(II) nitrate, bis(triphenylphosphine)palladium(II) carbonate and the like; complexes with phosphates'and phosphites, e.g., bis(fiioctylphosphite)palla dium(ll)nitrate; Ibis(triphenylphosphate)palladium(l1) chloride, and the like; complexes with bidendate ligands of the types outlined above may also be used.

Palladium metal in an active form such as palladium black or palladium on a support, such as charcoal, may be used as the source of the catalytic palladium species. Palladium complexes can be generated in situ by reaction of such active forms of palladium with species such as allyl bromide (to give ar-allylpalladium bromide) or trihydrocarbyl phosphines.

In addition to the palladium compounds listed, .the analogous compounds of platinum are well known and are also efiective as catalysts in the process of the invention.

While any one of the palladium or platinum compounds previously described can be used as catalysts, improved results can be obtained by the addition of catalyst modifiers.

The modifiers can be selected from the trihydrocarbyl (th'e trialkyl, triaryl and alkaryl arsines illustrated by substitu tion of As for P in the compounds described above) and the trihydrocarbylphosphites (trialkylphosphites, e. g.,

phosphite, tris(2-ethoxyethyl)phosphite and the like; triarylphosphites, e.g., triphenylphosphite, tri(p-chlorophenyl)phosphite, tri(1 naphthyl)phosphite, triorthotriethylphosphite, tributylphosphite, tri(2 ethylhexyl)- phosphines, for example, or mixtures of phosphines and/ or arsines and/or phosphites.v v

Compounds with both phosphorus to oxygen and phosphorus to carbon bonds, such as diethoxyphenylphosphine [(C H O) PPh], ethoxydiphenylphosphine, dimethoxyphenylphosphines, diphenoxyethylphosphine, diethoxybutylphosphine, and the like are also useful as catalyst modifiers. U k c Other phosphorus compounds which areiusefulin the reaction are bicyclic phosphites which include compounds of the general formula V in which R can represent a hydrogen; or an alkyl group, such as methyl, ethyl, isopropyl, nonyl, and the like; or an aryl group such as phenyl, tolyl, naphthyl, andthe like;

or a functionally substituted alkyl, such as hydroxymethyl,

ethoxymethyl, phenoxymethyl, hydroxyethyl, hydroxypentyl, acetoxymethyl, acetoxypentyl and'the like. These phosphites can be visualized as being derived as theprodnets of esterification of phosphorus acid ((HO) P) with triols of the general formula RC (CR' OH) where R is either hydrogen or some carbon containing radical. Another type of bicyclic phosphite that is useful as a catalyst modifier includes those compounds of the general formula shown below: I o-cHl-orn-o R--P\ P-R' 0-CHr-CHz-O In this instance, R and R can be hydroxyl, hydrogen, alkyl, aryl, alkyloxy, aryloxy and'the like as illustrated for the R group of the 'bicyclic phosphites described above. These modifiers may be added to the reaction mixture in quantities such that, the ratio of 'the total number of moles of modifiers of all kinds (whether added as part of the palladium or platinum catalyst or added separately) to palladium or platinum, can vary, for example, from 200:1 and higher and 1:10 and lower, preferably from 100:1 to 1:1, mostly preferably 20:1 to 1:11 The catalyst is employed in catalytically significant quantities. A palladium concentration in the range from about 0.00000 molar and lower to about 1 molar and higher is suitable. A catalyst concentrationin the range from about 0.0001 to about 0.1- molar is preferred. For

, optimum results the nature of the reactants, the operative conditions of the reaction; the-solvent characteristics of the carboxylic acid and amine employed (and any inert normally liquid organic diluent, if employed) and other factors will largely determine the desired catalyst concennation- :1. i J .l The catalyst is a combination of the activet'ransition metal (e.g., palladium) and a ligand such'ias a For As compound as previously described. These catalystscan be formed in situ or preformed and"charge'd'tothe'reaction initiallyl, l '1 5 Kill The carboxylic acids whi'ch'are' contemplated inthis novel process contain at least one carboxy' group,' i.e., COOH. Illustrative examples of these carboxylic acids are acetic acid, chloroaceticjacid,'propionic acid, butyric acid, isobutyric acid, valeric acid; hexanoic acid, heptanoic acid, dodecanoic acid and the like the cycloalkariecarboxylic acids, v e.g., cyclohexanecarboxylic acidand cyclopentanecarboxylic acid and the like'garomatic'acidssuch as benzoicfacid, naphthoic acid, phenylacetic acid and the phenylene diphosphite, and the like. Mixed alkylar'y'l- Because of considerations such, as solubility, it may" T be advantageous to use mixtures of different hydrocarbylphosphites can be prepared and usedpBecau'se of the l'malonic J acid, adipie acid, a ent; sai phthaliclaci' phthalic and/or,terephthalicadid-and-the like.

like; and monocarboxylicacids with carbon-carbon" nsaturation such as acr'ylic' acid, butenoic';acid,, oleicfacid,

undecenoic acid, ,cinnamicyacidfisorbic acid, and (the like; half acid esters or half dialkyla'mides' of 'clicarboxylic acids; ;as well .as the dicarboxylic r acids themselves, ,f su ch" as direct use of dibasic,aciils, .suehi as fphthalic provides an interesting .embodiment of the invention in that it is possible to synthesize the dioctadienyl phthalates, which fcan be hydrogenated under mild conditions to give dioctyl phthalates, the desired plasticizers, directly. This amine can vary from 50 to 0.1 mole of carboxylic acid per atom of N in the added amine, but the preferred range is 10 moles to 0.3 mole of carboxylic acid per atom of N in the amine.

avoidsjhe hydrolysis step in the recovery of the octadienols The ratio of butadiene to carboxylic acid can vary from the actadienyl esters which has been previously diswidely but the more butadiene present relative to the cussed; In the hydrogenation of the dioctadienyl phthalcarboxylic acid the faster the rate of reaction. The ratio ates, the olefinic bonds in the alcohol residue are hydroof butadiene t0 carboxylic acid can vary from 0.01-50 genated much'rnore readily than the aromatic double moles of butadiene per mole of carboxylic acid with a bonds, and the hydrogenation can readily be carried out ratio of 0.2-8.0 moles of butadiene per mole of carboxylic under known conditions using typical hydrogenation cataacid being preferred. lysts,s'uch as Raney nickel. Purified butadiene need not be used and instead the In the general reaction, butadiene may be replaced 0.; stream from an olefin plant, the usual feed to a buwith other 1,3-dienes to form substituted octadienyl esters. tadiene refinery, can be employed in the reaction. This C Suitable 1,3-dienes include isoprene, piperylene and 1,3- stream is a mixture of butadiene and butenes with smaller hexadiene. amounts of other hydrocarbons. When using such a A special effect of the tertiary amine modifiers is noted stream, the molar ratios of diene to acid and acid to in the reaction of butadiene With acrylic acid. In this inamine are still applicable to the invention as are the limistance, the competing effect of the Diels-Alder reaction of tations on palladium concentration levels. No products are butadiene with acrylic acid is possible, and, indeed 00- observed that could be interpreted as coming from the recurs to a significant extent in the absence of a tertiary action of butenes with the carboxylic acid under these amine- H e in e P e of the tertiary amine, non-oxidizing conditions. This is further proof that this the dierlolfthile function of the acrylic acid is d, and inventon is fundamentally different from the olefin-acetic n y negligible amounts of the Diets-Alder Product are acid reactions described in US. Pat. No. 3,221,045 issued produced. to I E. McKeon and P. S. Starcher. "The octadienyl acrylates formed are again mixftures of EXAMPLES 1octa-.2,7-dienyl acrylate with smaller amounts 0 3-octa- 1-,7- dienyl acrylate. These are useful monomers for mak- I Expenmental techmflues acrylic polymers n copolyme'rs with ethyl acrylate, Two sizes of reactors were used in these experiments. which can be cross-linked through the double bonds of S a runs were made 111 Pyrex Pressure tubes to the alcohol residue to form insoluble polymers. These whleh the reactants were charged and the tubes app doubly unsaturated acrylates can also be copolymerized r arr Ordmary bottle PP some p were eq pp with ethylene to form cross-linkable polyethylenes of imwlth heal/Y rubber seals a holes. through whleh pro'ved stiffness and durability. The can also be bro- P s could h remeved usrrlg lf u were minated and used in polyester formftion of increase the 5 a wlth lrlterrhltteht agltatlorl In all 011 or Water .bath fi resistance f the products preheated to the deslred temperature.

The-reactions of the present invention can be carried ge runs were made 1n a three Prht1 s1Ze Chemco out by charging the carboxylic acid, the amine, the pallaglass reactor *eq pp with a meehahleal r- T dium compound, and the ligand modifier to a suitable presaetarlts were charged were y pa g steam sure vessel and introducing butadiene. Other orders of ad- 40 or hot water through an Internal heatlrlg e911. Thls reae' dition of the reactants are also effective. The reaction can tor was also q pp with P tlrbe that sarrlples be carried out at --5 to 200 C. although the temperature Could he removed during reaetlorl for analysis y of the reaction is not a critical part of the invention. Pre- Vapor Phase ehrorrlatography ferred, reaction temperatures are 20 to 180 and most Identification desirably from to 125.0 The r be Compounds made in this work were isolated by distillacarried out at autogeneous pressures or higher if desired. tion and their Structures confirmed by nuclear magncfic Reaction can also be observed at atmospheric pressure and resonance Spectroscopy, infrared Spectroscopy and mental analysis. Once the structure of a compound was The rate and Yields of the reactlons e affected by firmly established, it was identified in subsequent runs the; relative concentration of acid and amlne w1th the its VPC r'etention time The following tables are self maximum rates and efficiencies being Obtamed when near explanatory and the experiments are intended as exameq im l r ratios of amine t0 earbexyhe acid are used- The ples of the invention but are not intended to necessarily effect of butadiene concentration on the reaction rate and 1 illustrate thejimitatigns f h i i efficiency is found to be dependent on the amine to car- In the abbreviations in the tables Pd(AcAc) stands for boxylic acid ratio, but in general the rate increases as the palladium acjetylacetonate and Ph P stands for triphenyl relative amount of butadiene increases. The molar ratio of phosphine.

r 1 TABLE I Butadiene-Acetic Acid Telomerizations Palladium-Triphenylphosphine Catalyst Eflects oi Amine Modifiers Product distribution Converpercent Reactoreharge moles sion of buta- 3-acetoxy .l-acetoxy- Example Temp., Time, diene, Octa- 2,7- Buta- Acetic No. Amine C. hrs. percent tr1ene octadiene ,0ctad1ene dlene acid Amine 1 1 N5... 90 '20 45 335.4 17.1 p 47.5 0.12 0.17

90 a 90 15.3 23.5 60.2. 0.20 0.10 0.07 90' 2 92 i 8.5 25.1 05.4 0.12 0.17 0.09 90 1 90 -9.0 24.0; 57.0 0.20 0.10 0.05 90 1 82 ;-7.6 25.4; 50.0- 0.10 0.10 0.10 90 i 1 6.9 31.0; 52.1 0.10 0.10 0.10 93 1 3 s7 12.7 12.7; 74.6, 52.0 5 2.0 1.9 2 2 as 5 as ii: 3:: iiiiiffitii iiiilgtfiiiifhasn521155.155:3"3 38 i 39 731 1811 7435 0: 20 0: 10 0:06 12. N,N,N',N-tetrameth 1-1.s-butanediamine 1.5 90 7.0 25.7 66.7 0.20 0.15 0. 03 1a N,N,N N-tetramethylethylenediamine 9o 20 52 -13 22 65 0.10 0.10 0. 05 14. Triethy en'ediamine 90 p 2.0 83 -10 25 05 0.20 0.15 0. 03 1 5. Hexamethylenetetramine'. 90 31. 0 46 31.8 20.6 47.6 0. 20 0,15 0.02 I .Ruhs made in 50 cc. Pyrex pressure tubes. Catalyst 0.25 males were 16% buten yl acetates but in all amine runs only minor amounts Pd(AcAc)z and 0.25mmoles Phil. were found.

a Yields based on converted butadiene. i Butenyl acetates formed included in this figure. In Example 1, there 4 Runs made in 3 pt. Chemco glass reactor. Catalyst 2 1111110105 Pd (AcAc)z and 2 moles P1111.

1 1 phenylphosphine were reacted at 90 C. for 20 hours, 80% of the butadiene was converted and the yield of octadienyl-benzoates was 63.3%, while that of octatriene was 36.7%. Thus, the use of the amine modifier had increased the rate of reaction about four times and improved the yields of desired products.

Example 52 (acrylic acid) To a glass-lined, two-liter, stirred Paar autoclave were charged 270 grams (5.0 moles) of butadiene, 360 grams (5.0 moles) of acrylic acid, 450 grams (4.5 moles) of N-methyl-morpholine, 3.3 grams (11 mmoles) of palladium acetylacetonate, and 3.0 grams (l1 mmoles) of triphenylphosphine. This mixture was maintained at 80- 90 C. for 3.5 hours to yield 1091 grams of liquid product. This exact procedure was repeated to give another 1038 grams of liquid product. The runs were combined and 2 grams of hydroquinone added as an inhibitor. VPC analysis on a 6-ft. silicone rubber column indicated the presence of 166 grams of 3-octa-1,7-dienylacrylate and 357 grams of 1-octa-2,7-dienylacrylate representing a total yield of 53 percent. The liquid product was then stripped through a molecular still to remove the majority of the product from the catalyst. A residue of 328 grams was left. The distillate was charged to a x 18" Vigreux still and a small amount of dimethylglyoxime added and then distilled at reduced pressure to yield 668 grams of a fraction, boiling point: 84-l33/9-3.3 mm., that was a mixture of octadienylacrylates and the N-methylmorpholine salt of acrylic acid. The heart" cuts, 418 grams, were combined and water washed several times until the VPC peaks representing impurities were removed. This resulted in 229 grams of a mixture of 27 percent 3-octa-l,7-dienylacrylate and 73 percent 1-octa-2,7-dienylacrylate, boiling point 85-87/ 1.3 mm. The structure of the mixture was confirmed by IR and NMR spectroscopy.

NMR data on both isomers is given in Table V.

There were charged to a glass-lined, 3-liter, stainless steel autoclave 180 grams (3.3 moles) of butadiene, 240 grams (3.3 moles) of acrylic acid, 300 grams (3.0 moles) of N-methylmorpholine, 2.2 grams (7.2 mmoles) of palladium acetyl acetonate and 2.0 grams (7.6 mmoles) of triphenylphosphine. This mixture was heated to 80 within 50 minutes and was maintained at 80-90" for 2.5 hours. The reaction product weighed 696 grams and VPC analysis indicated the presence of 103 grams of l-octa- 2,7-dienylacrylate and 47 grams of 3-octa-1,7-dienylacrylate, representing a 50 percent yield. The product was diluted with water and extracted with ether and the combined ether layers were washed three times with water. After removal of the ether, the residual material, 154 grams, was distilled at reduced pressure. A fraction, 44 grams, boiling point 4755/0.6 mm. was obtained. VPC analysis indicated that the octadienylacrylate isomers were contaminated, probably by the N-methylmorpholine salt of acrylic acid. After several water washes this material was removed. The octadienylacrylate was distilled yielding a mixture that was 90 percent 3-octa-l,7-dienylacrylate.

NMR data on the produ ct is given in Table V.

Data on C H O (B. 'pt., 6l62/0.8 mm.); percent: C, 73.38; H, 8.94. Calcd. for C H O percent; C, 73.3; H, 9.0.

Example 53 (phthalic acid) A mixture of 6.0 grams of butadiene, 3.3 grams of .phthalic acid, 1.4 grams of N,N,N,N-tetramethyl-l,3 butanediamine, milliliters of N,N-dimethylacetamide,

0.076 gram of palladium acetylacetonate and 0.060 gram lcent hydrochloric acid followed by washing with a sat- 12 diester present-bis(octadieriyDphthalate. The solution was hydrolyzed with a 25 percent potassium hydroxide solution to yield octadienol. 1

Example 54 (separation of products by azeotropic distillation) 1A1! overhead product from a stripped reaction mixture analyzed as follows: 5.4% acetic acid, 3.5% octatriene, 16.5% tetramethylbutanediamine, I 18.5% 3-acetoxy-1,7- octadiene (3-OAc) and 56.1% l-acetoXy-ZJ-octadiene l-OAc). This mixture (984 grams) was fractionated using a 4-ft. x 1-in. packed grapenutidistillation column. The distillation is summarized below:

- Area percent from thermal detector VPC Wt. 01 B.P.lmm. Out No cut (g.) Hg. HOAe Amine S-OAc l-OAc 3055/4 4. 6 35. 4 31. 5 56-60/4 14. 4 27. 7 58. 4 1. 5 0-61/4 9. 1 32. 4 1 57. 4 1. 1 60-61/4 11. 6 29. 3 59. 1 60-62/4 5. 0 65. 8 28. 9 0. 3 60-62/3. 6 10. 6 40. 7 40. 3 8. 4 62-63/3 5 16. 9 30. 2 I 6. 1 46. 8 62-64/3 0 21. 9 19. 6 1. 6 59. 9 6244/3. 0 23. 1 Y 18. 7 Y 1. 1 57. 3 6568/2.0 ..'...4 .5 99.5

The products were cleanly sprung from amine and acetic acid by the addition of water. The water insoluble products were separated from the water layer, washed again with water and dried over sodium sulfate.

It will be noted that the 3-isomerdistilled over with the amine as an azeotrope, leading" to the recovery of the l-isomer practically free of the. secondary ester.

Example 55 (platinum; catalyst) The following experiment was run according. to the capped tube technique previously described. The charge was platinum acetylacetonate (0.25 mmole),=triphenylphosphine (0.25 mole), butadiene (0.2 mole), acetic acid (0.1 mole) and N,N'-tetramethyl-1,3 butanediamine (0.03 mole). These materials were reacted at C. for 18 hours to give an 88% conversion of butadiene. The product was 6% 1,I'a,7-octatniene,27.3% 3-acetoxy-1,7- octadiene and 66.7% 1-acetoxy-2,7-octadiene.

What is claimed is: a

1. Process for converting butadinej to octadienyl esters which comprises reacting butadiene under non-oxidizing conditions with a carboxylic acid in the presence of a palladium or platinum catalyst and a tertiary amine having a basicity constant K greater than 10"" and recovering said octadienyl esters from the reaction products, said carboxylic acid being selected from the group consisting of aliphatic and aromatic monoand dicarboxylic acids and the ratio of carboxylic acid to tertiary amine being from 10 moles to 0.3 mole of carboxylic acid per atom of nitrogen in the amine. 3

2. Process for converting butadiene to octadienyl esters which comprises reacting butadiene under non-oxidizing conditions with a carboxyliclacid in the presence of a palladium or platinum catalyst and a tertiary aliphatic amine, and recoveringsaid octadienyl :esters from the reaction products, said carboxylic acid being selected from the group consisting of aliphatic and aromatic monoand dicarboxylic acids and the ratio of carboxylic acid to tertiary amine being from 10} moles to 0.3 mole of carboxylic acid per atomof nitrogen in the amine.

3. Process as claimed in claim 2 in which the carboxylic acid is acetic acid. H 1

4. Process as claimed in claim 2 in which the carboxylic acid is acrylic acid. ii

5. Process as claimed in claim 2 in which the tertiary aliphatic amine contains oxygen bonded; to carbon.

6. Process as claimed in claim 2 in which the amine is an aliphatic tertiary diamineii 7. Process as claimed in claim 2 in which the amine is triethylamirie. 2

8. Process as claimed in claim 2 in which the amine is dimethylethanolamine.

9. Process as claimed in claim 2 in which the amine is N-methylmorpholine.

10. Process as claimed in claim 2 in which the amine is triethylenediamine.

11. Process as claimed in claim 2 in which the amine is N,N,N',N'-tetramethyl-1,3-butanediamine.

12. Process as claimed in claim 2 in which the catalyst is a palladium compound complexed with a phosphite ligand.

13. Process as claimed in claim 2 in which the catalyst is a palladium compound complexed with a phosphine ligand.

14. Process as claimed in claim 12 in which the phosphite ligand is triphenyl phosphite.

15. Process as claimed in claim 12 in which the phosphite ligand is trimethylolpropane phosphite 16. Process as claimed in claim 13 in which the phosphine ligand is triphenyl phosphine.

17. Process as claimed in claim 12 in which the palladium compound is palladium acetylacetonate.

18. Process as claimed in claim 12 in which the palladium compound is palladium acetate.

19. Process as claimed in claim 13 in which the palladium compound is palladium acetylacetonate.

20. Process as claimed in claim 13 in which the palladium compound is palladium acetate.

21. Process as claimed in claim 13 in which the catalyst is tetrakis(triphenylphosphine) palladium (O).

22. Process as claimed in claim 13 in which the catalyst is bis(triphenylphosphine) palladium carbonate.

23. Process as claimed in claim 2 in which the carboxylic acid is a phthalic acid.

References Cited UNITED STATES PATENTS 3,534,088 10/1970 Bryant et al. 260497 3,403,108 9/1968 Leftin 260 -486 3,407,224 10/ 1968 Smutny 260497 A 3,417,133 12/ 1968 Harris 260-497 A LORRAINE A. WEINBERGER, Primary Examiner P. J. KILLOS, Assistant Examiner US. Cl. X.R.

260410.9 N, 468 R, 469, 476 'R, 485 N, 486 R, 487 497 A 

